The Borland Enterprise Server Console displays state icons for many objects
in its Navigation Pane. One of these is the "Obey Dependencies" icon:
This icon is most closely associated with user-created clusters. When you create a cluster, you create a logical framework of application resources that can be started and stopped as a coherent whole, although the Partitions and BES Server instances that make them up may be on different machines. For example, a cluster's server tree may look like the following:
You'll note the cluster PetstoreCluster at the top of the tree.
Every child node of the PetstoreCluster (and by extension the PetstoreCluster
itself) is a managed object. Child nodes such as the PetstoreServer-001,
the Apache Server ApacheOne, and the JDataStore and Sonic instances
"obey" the status of the PetstoreCluster. If the PetstoreCluster
is supposed to be running, the Borland Management Service makes sure that all
its dependencies are running as well.
The following diagram shows which components start and stop the others. This is an important diagram, for it shows that you cannot simply assume that a managed object's child-node is started and/or stopped by its parent.
The blue arrows indicate start direction. When you start a cluster, it in turns issues start commands to the JDataStore, SonicMQ, and the Managed Apache domain, assuming these are necessary. The Apache domain (the Managed Apaches node in the Clusters View), in turn, invokes the necessary Apache 2.0 service, which starts the BES Server instance necessary for it to run.
At the same time, the cluster invokes a start command on the Smart Agents (osagent) and Partitions that make up the cluster's definition. These components start the necessary BES Server instances necessary for them to run.
The red arrows indicate stop direction. When you stop a cluster, it in turns issues stop commands to the JDataStore, SonicMQ, and the Managed Apache domain, assuming these are necessary. The Apache domain instructs its managed servers to stop, and those in turn terminate the Apache process associated with the cluster.
At the same time, the cluster instructs its associated BES Server instances to stop, and those in turn terminate the Smart Agent and Partition processes associated with the cluster.
